t4202: mark bogus head hash test with REFFILES

In reftable, hashes are correctly formed by design.

Split off test for git-log in empty repo.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Reviewed-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t4202-log.sh b/t/t4202-log.sh
index 327991f..39e746f 100755
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh
@@ -1834,14 +1834,20 @@
 	test_must_fail git log --graph --no-walk
 '
 
-test_expect_success 'log diagnoses bogus HEAD hash' '
+test_expect_success 'log on empty repo fails' '
 	git init empty &&
 	test_when_finished "rm -rf empty" &&
 	test_must_fail git -C empty log 2>stderr &&
-	test_i18ngrep does.not.have.any.commits stderr &&
+	test_i18ngrep does.not.have.any.commits stderr
+'
+
+test_expect_success REFFILES 'log diagnoses bogus HEAD hash' '
+	git init empty &&
+	test_when_finished "rm -rf empty" &&
 	echo 1234abcd >empty/.git/refs/heads/main &&
 	test_must_fail git -C empty log 2>stderr &&
-	test_i18ngrep broken stderr'
+	test_i18ngrep broken stderr
+'
 
 test_expect_success 'log diagnoses bogus HEAD symref' '
 	git init empty &&